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151.
Affirmative action is a new variety of selection rule which employs historical information to favor the choice of elements that have not been selected in the past. We categorize three implementations of this principle and discuss their application to the simplex method, to Bard-type schemes for the linear complementarity problem, and to augmenting path methods for network flow problems. We present analytical and computational results, and some open questions.Research supported by the Georgia Institute of Technology.Research supported by the New Faculty Research Development Program of the Georgia Institute of Technology. Reproduction in whole or in part is permitted for any purpose of the U.S. Government. 相似文献
152.
153.
Thin films of ZnSe and PEO–chitosan blend polymer doped with NH4I and iodine crystals were prepared to form the two sides of a semiconductor electrolyte junction. ZnSe was electrodeposited
on indium tin oxide (ITO) conducting glass. The polymer is a blend of 50 wt% chitosan and 50 wt% polyethylene oxide. The polymer
blend was complexed with ammonium iodide (NH4I), and some iodine crystals were added to the polymer–NH4I solution to provide the I−/I3−redox couple. The room temperature ionic conductivity of the polymer electrolyte is 4.32 × 10−6 S/cm. The polymer film was sandwiched between the ZnSe semiconductor and an ITO glass to form a ZnSe/polymer electrolyte/ITO
photovoltaic cell. The open circuit voltage (V
oc) of the fabricated cells ranges between 200 to 400 mV and the short circuit current between 7 to 10 μA. 相似文献
154.
155.
Rahim Hekmatshoar Majid M. Heravi Yahya S. Beheshtiha Karim Asadolah 《Monatshefte für Chemie / Chemical Monthly》2002,133(1):111-114
Summary. Aldoximes can be efficiently and rapidly dehydrated to nitriles by treatment with phthalic anhydride under microwave irradiation.
Received April 18, 2001. Accepted (revised) June 7, 2001 相似文献
156.
Yahya Ould Hamidoune 《Journal of Combinatorial Theory, Series B》1981,30(1):108-112
A conjecture of Slater states that Kh + 1 is the unique k-critically h-connected noncomplete graph for 2k > h. We prove here that there is no k-critically h-connected connected graph with order . We prove also that there is no k-critically h-connected line graph for 2k > h. The last result was conjectured by Maurer and Slater. We apply in our proofs a method introduced by Mader. 相似文献
157.
158.
Solute exchange experiments for the pyrene-labeled triglyceride TG-Py solubilized in sodium dodecyl sulfate (SDS) micelles in the presence and absence of salt show that the "observed" rate constant k(obs) for solute exchange varies by over 6 orders of magnitude as the free sodium ion concentration [Na(+)](aq) is varied between 10 and 850 mM. There is a sharp break in the log-log plot of k(obs) versus [Na(+)](aq) in the range of [Na(+)](aq) = 200 mM, with the exchange rate showing a weaker dependence on [Na(+)](aq) above this concentration. Up to 100 mM added NaCl, this exchange takes place essentially exclusively by a micelle fission mechanism in which each submicelle carries off one of the solutes. At higher salt concentrations, a bimolecular process becomes increasingly important. This fusion process, which involves formation of a transient supermicelle followed by fission back to two normal micelles, becomes the dominant process at high salt concentrations. The fission rate appears to level off for salt concentrations above 300-400 mM. These fission and fusion processes are related in an intimate way to the changes in the size and shape of the SDS micelles with increasing salt concentration. 相似文献
159.
Priyadarshini S. Mainal Azizah Sonsudin Faridah Yahya Rosiyah Alyousef Abdullah A. Mohammed Arshad 《Research on Chemical Intermediates》2020,46(2):1077-1089
Research on Chemical Intermediates - Antibacterial titanium dioxide nanoparticles (TiO2NPs) were biologically synthesized by microwave irradiation of Cissus quadrangularis extract followed by... 相似文献
160.
Arash Ghorbani‐Choghamarani Mohsen Nikoorazm Hamid Goudarziafshar Zahra Naserifar Parisa Zamani 《中国化学》2011,29(4):731-734
A mixture of ammonium nitrate or nitro urea and silica sulfuric acid was found to be efficient and environmentally friendly nitrating media for the preparation of orto‐nitro phenols in dichloromethane at room temperature. 相似文献